Treasures that scientists keep on ice

Scampering Salamanders!

My team had a new technician arrive, Kyle Chadwick from Uni. Virginia, and NSF Postdoctoral Research Fellow, Dr. Ashley Heers (see here for an example of new stuff she’s starting here at the RVC!), started working with me at the RVC, and then these guys showed up…

But then we got a special package… with three frozen fire salamanders (Salamandra salamandra) from colleagues in Germany!

Three new occupants of the freezers, for planning our studies of salamander locomotion

This marks the start of an exciting new period in my team’s work in the lab. I’ve always liked salamanders and newts, and we’ve scanned and modelled plenty (e.g. this old post), but now we’re going to work with live fire salamanders (a first for me)! We are using the dead ones to plan the new studies with the live ones– these new studies will involve lots of high speed videos and force platform analysis (as shown above), in conjunction with XROMM (biplanar fluoroscopy/3D skeletal motion analysis) and other techniques including computer simulations. We got initial approval this week to work with these salamanders, and found a reputable source this week too, so it was definitely Salamander Week in my group!

This research all will feed into our upcoming studies of extinct tetrapods: we’re using salamanders to figure out how salamanders move and what limits their speed and gait, and then we’re using the same sorts of computer tools to try to estimate how extinct tetrapods may have moved and how locomotion evolved, in much more specific detail than our prior work had done, which was mainly about using 3D reconstructions of anatomy to show what those animals could not do. More about the project here.

Watch this space for more scampering salamanders!

UPDATE: And here’s one! Not quite scampering, but…

Setting up our two fluoroscopes for a test run of our gait studies– but with one of the deceased salamanders. Gotta get good images before any live animal work begins!

An example of the kind of footage we’re aiming for (single 2D fluoroscope view from Nadja Schilling’s team’s research; see XROMM website for more details on the methodology)

UPDATE 2:

I did a CT scan with a normal medical grade CT scanner at the highest resolution we can manage (0.625 mm slices). Check out the results below, which amuse me:

Looks like a toy; too crude resolution. But we can see major structures, and we can very nicely see the “microchip” (which looks HUGE) that was placed in this animal’s back when in captivity, and then another structure is visible near the pelvis which might be another chip or else remains of some food, pathology, or a really odd pelvis– I am not totally sure!

So this is why we tend to use microCT, which can go down to as low as ~5 micron resolution, to get 3D anatomy of animals this small. It’s no surprise to me, but it is fun to see how far we could push our normal CT machine. The results aren’t horrid but wouldn’t have much scientific value for us. They did confirm for us that this specimen is heavily ossified, so the faint images of bone that we are getting in our x-ray fluoroscopes (above) are due to something going wrong with our camera system, not the animal’s immature skeleton. Stay tuned for more updates as the science happens!

UPDATE 3:

20 wonderful adult Fire Salamanders have joined our team and are relaxing over the coming week before we start taking them for walks. Here is one exploring its new home:

UPDATE 4:

August 11-15, 2014 we are in Jena, Germany using their fancy biplanar radiography system (“x-ray video”) to study our salamanders, at last! Follow the tweets starting here, for more information as it happened! https://twitter.com/JohnRHutchinson/status/500187568416518144

6 Responses

“..likely motions used by the earliest land vertebrates, in order to reconstruct how locomotion on land first evolved.”

“…the ability to stand on all four legs seems to have evolved after the appearance of fully developed limbs with digits and other skeletal features which are now thought to have arisen in aquatic animals.”

{“evolutionary pioneers”}

“This raises the question: when and how did modern walking styles evolve?”

“Furthermore, were all tetrapods similarly sedate or could some forms move more quickly than others?”

“The technology and biological understanding now exists to answer such fundamental evolutionary questions.”

“This project will uncover how evolutionary changes in anatomy impacted the ways in which early tetrapods could move, ultimately illuminating how vertebrates eventually conquered the terrestrial realm.”

“Further, it will advance the field of evolutionary biomechanics by creating a novel simulation approach, firmly grounded in empirical data, which will be distributed to scientists studying locomotion in living and extinct organisms.”

These aren’t words of absolutes…no one said that they are. This is a field that has a lot of questions and people who think there are concrete or partial absolutes are stuck in hope of easy answers. Evolution must have questions.

If not, what is the point of continuing the scientific studies? We might as well just quit. But we won’t. There is too much riding on the belief of a simple answer. Too many variables and too many people who won’t think critically.

[…] (Salamandra salamandra)! We love ‘em, and the museum had several on display- given that we were studying them with x-rays, seeing the skeleton and body together here in this nice display was a pleasant […]